The present invention relates to a high pressure pump such as a high pressure fuel pump that supplies fuel to the fuel injector of a vehicle internal combustion engine.
Japanese Unexamined Patent Publication No. 8-68370 discloses a high pressure pump, which is illustrated in FIG. 4.
As shown in FIG. 4, a cylinder 41 accommodates a plunger 42. The plunger 42 extends through a plunger hole 41b formed in the cylinder 41 and is reciprocated by a lifter 43. Reciprocation of the plunger 42 changes the volume of a pressurizing chamber (not show), which is defined in the cylinder 41. Accordingly, fuel is pressurized.
A seal member 44 is located about the lower portion of the cylinder 41 to seal the space between the cylinder 41 and the lifter 43. Specifically, a protrusion 41a is formed in the lower portion of the cylinder 41. The protrusion 41a is press fitted into the upper opening of the seal member 44. An annular lip portion 44a is formed in the lower portion of the seal member 44. The plunger 42 extends through and slides on the lip portion 44a. Thus, fuel that leaks from the pressurizing chamber is prevented from being mixed with lubricant that lubricates the lifter 43.
However, since the protrusion 41a of the cylinder 41 is press fitted into the upper opening of the seal member 44, the cylinder 41 receives load due to the elastic force of the seal member 44, which may deform the plunger hole 41b. 
The axes of the seal member 44 and the plunger 42 must be aligned with a high precision to guarantee a high sealing characteristic, which increases the cost of the cylinder 41.
Accordingly, it is an objective of the present invention to provide a high pressure pump the seal member of which is reliably installed and positioned outside of a cylinder.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, a high pressure pump is provided. A plunger is reciprocally located in a pressurizing chamber that is formed in a cylinder. The plunger is reciprocated by a driving member and changes the volume of the pressurizing chamber thereby pressurizing fluid in the pressurizing chamber. The pump includes a seal member and a support. The seal member is located outside of the cylinder and seals the cylinder from the driving member thereby preventing fluid that leaks from the pressurizing chamber from being mixed with lubricant that lubricates the driving member. The support is formed separately from the cylinder and the seal member is attached to the support. The support is fixed to the cylinder with the plunger extending through the support.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.